CD19 and rheumatoid arthritis: Initial cellular phenotyping by flow cytometry revealed that RA and RA-risk individuals have increased frequencies of CXCR3+CCR6−CCR4− Th1 cells (19), ILC1 (c-Kit-NKp44− ILCs) (20), memory CD8+ T cells (21), CD69+CD8+ T cells and more CD19+ B cells compared to healthy controls (9).